Extra funding was approved last year to allow President Barack Obama ample time to make a decision on the future of the F-22 program.

Some lawmakers, particularly those from states where the planes are assembled like Georgia and Texas, say cutting off spending for the aircraft will result in thousands more lost jobs amid a global recession that already has left millions of workers unemployed.

Morrell cautioned, however, that plans to provide Congress with an update "should not necessarily signal where we are going with the F-22 program."

The Obama administration was expected to decide by March 1 whether to spend $523 million on 20 more of the radar-evading planes beyond the 183 jets already planned.

However, that decision won't become clear until the fiscal 2010 defense budget is released to Congress in mid-April, Morrell said.

The supersonic jet has enjoyed strong support on Capitol Hill, but Defense Secretary Robert Gates and Air Force officials have differed over the future of the program and the number of planes needed.

Even if the Pentagon opts not use the rest of the $140 million that was obligated, the materials already purchased could be used to build other aircraft, like Lockheed's Joint Strike Fighter, Morrell said.

Most of the aircraft are being built by Lockheed in Georgia and Texas. Boeing Co. manufactures the wings and other parts in Seattle. The engines are supplied by Pratt & Whitney, a United Technologies Corp. unit, in Middletown, Conn.